Is Wd 40 Safe For Septic Tank and How to Maintain Septic System?

WD 40 is currently amongst the most popular household water-displacing sprays to remove rust, oil, grease, etc. However, is WD 40 useful for every time and for every house, especially those with septic toilets?

This article will briefly answer the question “Is WD 40 safe for septic tank” and give you some additional information to maintain your septic tanks. 

Photo by Andy Rogers

Is WD 40 Safe for Septic Tank?

The short answer is: No, WD 40 is not safe for your septic tank.

The long answer is: There are safety-related reasons why we can conclude WD 40 is a danger to your septic tanks. 

But before understanding why WD 40 is terrible for a septic system, you should know how the septic tank works in reality. Inside your septic tanks, there is a massive ecosystem of organisms. And these super-small entities will help tanks to function well. 

These microbes break down waste and convert it into liquid or gas. Accordingly, septic tanks push these final wastes into the drain field quickly.

However, some substances will destroy the ecosystem of bacteria. Petroleum oil is one of those chemicals. And, unfortunately, the main ingredient of WD 40 is petroleum base oil. 

When petroleum oil reaches down inside septic tanks, it will kill all bacteria down there. More dangerously, petro oil is non-biodegradable. And it is only a matter of time when this dangerous oil finally reaches someone’s drinking water. 

What Alternatives for Wd 40 to Use for Septic Tank?

We all agree that WD 40 is a useful household degreaser. But, for cleaning your septic tank, WD 40 is not the right choice. There are some other alternatives for WD 40 when you want to clean and maintain your toilets. 

Natural Products

The best option is natural cleaners such as lemon juice, baking soda, vinegar, citronella, etc. You can also try some formula to make up your cleaning water that smells relaxing and does no harm to septic tanks. Natural formula is also an environmentally-friendly and affordable method for anyone.

Water-based Products

Water-based cleaners work well on septic tanks, too. These cleaners have water as their main ingredient, and water can dilute other harmful chemicals. 

We can pick any cleaning products that suit our favorites. There are, however, two essential things to remember for our safety: No to harsh chemical overuse and Yes to natural cleaners. 

Products with Low Chemical Levels

Household liquid bleach or products with low ammonia levels are worth considering due to their cleaning power. Although some articles state, these chemicals are not suitable for septic tanks because they can kill bacteria. 

The truth is, a small amount of them cannot destroy the bacterial ecosystem inside tanks. However, overusing these substances on your toilet is not recommended.

What Don’t You Put in a Septic Tank?

To maintain septic tanks in good condition, there are a few things you should not flush into the tanks as well. 

It is essential to know that a specific cleaning product is intended for specific use only. For example, you cannot clean the toilet by flushing laundry powder. Even if you like the laundry powder a lot, it will damage your septic tanks. 

Products like powder laundry detergent, fabric softener, drain cleaner, or antiseptic soaps are not for cleaning septic toilets. This is because these products can contain petroleum oil or a large amount of clay, sodium, which will damage bacteria’s life.

Paint thinners, paint, and latex paint are detrimental to your toilets. Because these products have a high amount of oil, once you send paint into the toilet, you deal a blow to the septic system.  

It would be best if you did not flush any solid things into the toilet because it will make your septic tank be filled quickly. People throw everyday items into the toilet, like coffee grounds, cigarette butts, earplugs, tampons, and dental floss. All of them will serve nothing to help your tanks. 


Question 1: Is bleach harmful to bacteria in septic tanks?

The answer is both yes and no. It all depends on the amount of bleach you have poured into the toilet. Overusing bleach or using products with high bleach amounts can destroy septic systems. 

Question 2: Does homemade toilet cleaning product worth a try?

Yes, it does. As mentioned above, homemade cleaning products are easy to make, and you can also adjust their smell to your liking. One important thing is they should be made from natural components. 

Question 3: Can septic tanks be repaired?

Yes, they can. But they will cost you a significant amount of money and cause absolute inconvenience for your family. Therefore, any attempt to keep the septic system good is worthy. Anything you put into your toilet will affect the septic system.

In Sum

The final answer to the question “Is WD 40 safe for septic tank?” is definitely a No. WD 40 is not a wise choice for septic toilet cleaning. There are other alternatives that you can find on the market or create yourself.

Whatever you try to clean the toilet, remember there is an extensive system of bacteria down there. To keep those bacteria safe is to keep your family safe and healthy.

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